Michael Redgrave never expected much from his daughter Lynn. In his eyes, her sister, Vanessa, and brother, Corin, were the stars. Only now is Lynn exorcising that painful verdict.
Twelve years ago, when Lynn Redgrave's father, Sir Michael, was dying of Parkinson's disease, she flew from her home in Los Angeles to visit him. In the middle of the night at his country cottage she found that the jet lag made it hard for her to sleep, and she stole downstairs. Her father's diaries and personal papers were piled high, and she started to read them. She turned to the page in his diary for 8 March 1943, the day she was born. But the diary entry noted only the play that Sir Michael had been in that night, and how the performance had gone.

The father with whom she had never had a proper conversation in her life had not even taken note of her the day she was born. She decided not to look up the birth dates of her sister, Vanessa, or her brother, Corin. These, she felt sure, would have received lengthy entries - and that would have made her sense of rejection even sharper.

Lynn Redgrave is 53 years old, an acclaimed actress, a feminist heroine in America (where a decade ago she sued the all powerful Universal Studios which, she claimed, had fired her for breast-feeding in her dressing room). She is also still obsessed with her unresolved relationship with her father.

Her father's autobiography, written in his last years, referred to her thus: "It is hard for the child of whom great things are expected but harder by far for the one who is adorable and sweet and of whom no one expects very much."

The results of that peculiar condescension are still evident. It was decades ago that Lynn changed from being the painfully shy, overweight child "filled with self-loathing", and became a star at the National Theatre and in films such as Georgy Girl, then decamped to America for a happy family life with director John Clark, and a new, elegantly svelte figure and a California tan. But inwardly, little seems to have healed. Those who think one gets over a fractured father/daughter relationship should go to the Haymarket Theatre in London's West End from next week; they will think again.

In a one-woman show, Lynn will tell the story of the night she found the diary, and many other stories of her unfulfilled relationship with her father. Speaking of that moment now, she rapidly - and unconvincingly - tries to justify her father's behaviour. "I closed the book very quickly and I didn't tell anyone for a long time, not even my husband," she says. "I've made sense of it now. Why should I get upset? Look, there was an air raid on. Other things were happening." But sense seems to be the last thing she has made of it.

If Shakespeare For My Father, her one-woman show, is theatre therapy, then three members of next week's audience may have ambivalent feelings about it: her siblings Vanessa and Corin and her mother, the 86-year-old actress Rachel Kempson. Both Vanessa and, in particular, Corin have written about their late father, the knight of the theatre whose bisexuality was a closely guarded secret, and who suffered from Parkinson's disease for much longer than most people even now realise.

But, as the Redgrave family well knows, it is one thing for Vanessa and Corin, the adored and always encouraged apples of their father's eye, to discuss him. Lynn is another matter altogether. She was the child he rarely acknowledged, looked at stony-faced, never encouraged. She was the child who worried about it so much that it gave her an eating disorder.

Yet Lynn was the woman who spent time with her father when he was close to death's door, and when his illness was so advanced that he hallucinated that his hospital room was backstage at the theatre, and admonished Lynn for peeking at him through the curtain. "It's so unprofessional," he chided her, before bending towards her to inquire sotto voce, "by the way, how's the house tonight?"

The family was, to use Lynn's word, "diffident" about the project. Others close to the show say that her sister and brother wanted to stop it from going on at all. Lynn denies this, but she does add: "I didn't tell my family I was writing it, and when they found out about it they were nervous that it would be an invasion of their privacy. But they were too smart to ask me not to put it on. They would have known there was no way they could have stopped me. It is my story, not theirs. And I realised that I had never actually shown any of them how I really felt."

They are referred to in it, though. Lynn will re-create one childhood game on stage, when the gawky, shy youngest child was grateful to be invited by her older siblings to join in an acting game. Vanessa played the American president, Corin the British prime minister and Lynn the president's dog.

If the youngest Redgrave at the age of 53 has decided to exorcise some demons, then the Haymarket Theatre is the perfect place to do it. That was where she made her debut in The Tulip Tree in 1962, at the age of 19. The highlight for her was when her father came to see it, but disaster struck.

Lynn was playing a ballet dancer, and one of her fellow actors did not make his entrance on time. With considerable ingenuity she did the dance twice, then hummed it a third time, in the interminable wait.

"The rest of the play passed by in a haze. All I could think of was that Dad was there during this disaster. I waited for him to come around afterwards. His face - you couldn't tell if he had noticed or not, and I couldn't tell whether he had liked it or not. Years later I discovered in his book that he thought I had handled it really well. It would have been so easy for him to say that at the time. It was simply that he couldn't." She pauses, then adds, "But he could to Vanessa and Corin."

The play uses a number of speeches from Shakespeare. The most poignant is the speech of Cordelia to Lear: "I know my love is richer than my tongue."

"It so perfectly expresses myself and my father," Lynn says expressionlessly. "I loved him, and I couldn't speak. Just as my father couldn't really speak to me, I couldn't speak to my dad. I would see him round the dining room table talking eloquently about acting. I hung on his every word. But in my presence he became mostly inarticulate. It's not that we were at odds with one another. It was like there were a couple of pieces of soundproof glass between us. Even when he was dying, I couldn't bear the silence to fall. The silence was terrifying. It brought back all the fear that the silence brought when I was a child. It was the face I couldn't read. Was the face not moving because he was cross or displeased with me, or did he just not notice me standing in front of him?

"I'm not complaining, in the show, or seeking an easy answer. By the end I wish to convey that I've come to terms with it and remember the good things. It was a great privilege to be his daughter"n

`Shakespeare For My Father' opens next Wednesday at the Theatre Royal, Haymarket, London SW1 (0171-930 8800).